For hundreds of thousands of years, the global ecosystem has maintained its balance through absorbing carbon dioxide made by plants into oceans (1). By reducing atmospheric carbon dioxide levels, oceans have prevented the accumulation of naturally produced carbon dioxide in the atmosphere. By preventing these gases from accumulating, global warming was avoided (2). As well, oceans have developed mechanisms to compensate for this gradual and ongoing accumulation of carbon dioxide. When carbon dioxide dissolves in ocean waters, it turns into carbonic acid, which, as you may have guessed, is an acid. Ocean beds however are rich in calcium carbonate which is a basic entity. When the carbonic acid comes in contact with sea beds, calcium carbonate is pulled out and neutralizes the acid. This neutralization maintaining the pH balance in oceans. Through sustaining this neutralization pattern, sea beds have protected oceans from decreasing pHs, increased acidities and the world from rising atmospheric carbon dioxide concentrations (1).
In the last few centuries, oceans have acted as a reservoir for excessive man-made carbon dioxide emissions that are involved in global warming. Although increased absorption of these greenhouse gases has been helpful in shrinking the effects of global warming, their increased concentration in waters have disrupted the essential chemistry of oceans (2). Evident by over-eroded deep-sea rock beds and a 30% increase in ocean acidity in the last 200 years, oceanic carbonic acid levels have risen above levels that are able to be controlled by deep-sea sediments (1,2). To date, a meta-analysis has shown that ocean acidification has negatively impacted the livelihood of many ecologically important organisms such as calcifying algae, corals, coccolithophores, molluscs, and echinoderms (3). Ocean acidification is of particular concern in Canada’s arctic as carbon dioxide dissolves more readily in cold water compared to hot (2).
Disturbances caused by ocean acidification present both social, ecological and economic issues specifically for Canadians (2). The Arctic Ocean Acidification Assessment released in 2018 stated that ocean acidification is predicted to impact many animals and organisms in Northern Canada which will result in the disruption of entire ecosystems located in that region (4). Specifically, the assessment predicts there to be a significant decrease in arctic cod populations. A decrease in such a population could present significant difficulties for Inuit populations that rely on such fish as a food source. As well, this decrease in cod may impact beluga whales and ringed seals survival. Both of these animals are important for the maintenance of arctic ecosystems and hold cultural significance for the Inuit populations (3). As well, current studies have shown that Atlantic cod larvae, which holds significant value to Canada’s economy, have had markedly decreased survival rate as ocean acidity levels have been rising. Moreover, studies predict that larvae that survive acidified water will likely have impairments in bone and vital organ development later in life (5).
Globally, ocean acidification has had a particularly negative impact on coral reefs. Increasing acidity has been found to decrease the survival of organisms that build and calcify reefs (6). A decrease in such species decreases calcification of reefs which adds to reefs destruction. Specifically, in the Great Barrier Reef, the world’s largest coral reef in the world, ocean acidification is expected to add to the loss of biodiversity, decreased resilience, and potential to recover from other ecological insults like coral bleaching (7). Reefs are extremely important in the earth’s ecosystem as they play a big role in the nurturing of new species and help very diverse ecosystems flourish (6).
As carbon emissions continue to rise and oceans continue to absorb more carbon dioxide, Canada and coral reefs continue to be at risk in multiple ways. We must work together to reduce our carbon footprints in order to protect the Canadian economy, ecosystems, and populations that rely on non-acidified oceans.